Weird crashesh when giving 20v and solder heating up more then 500°c

[Rtyuakatsuki]

Hallo i have problem about when using 20v power supply or 19v+
It pretend weird when give power more then 19v

How can i fix it ?
I see your update just pull off (not use the zener 18v)

I kinda hesitant about it
And i wanna try the 20v power
I need faster heating
That why i ask for the solution what i need to do to fix it

I use board from local youtuber i got
Fareed read
Here the link board schematic

https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEitz7ZCWq4CHpV2WZGww2bgKEEEbje4CBCZLly9iTcXJruOM4NMSV36XI12CHHk9Jenuw0BcbYYxRtse0hr5YZCM6x_k3Vh-BbzjC0wccpHDqx9-WM4c4vuHTEzO_zFS8a5FvDoloVhuxW6UzK4Hva-xYl9dvyhrzmeJmUU9PbRo4H2ezq0gMT8AS17GA/s1750/ATmegaSolderingStation%20l.jpg

[wagiminator]

Have you tried using a different 20V power supply? The Zener diode is only there to protect the MOSFET.

[Rtyuakatsuki]

I tries 2 power supply
First 19v 60 watt laptop power supply from asus
And second from lenovo 20v powersupply with power 240watt

Yes got same problem
After some minute it weird glitch came out and messed up
The value default temprature or adc reading

And i check the adc reading also weird
When i turn on the board adc reading was started with
250+ value

When i plug cheap 12v 3a power supply it was running good

And after couple hour after i posted that
I check the ic pin d10 sleep mode
It shorted to ground
So i was ordering alternative
Atmega328p
LGT8F328p

Hope can work on it

So the main question
What make it happen ?

And more detail
I tried search about ADC problem
With power supply
It cause by noise from the power supply

But it kinda weird
Expensive server power supply
Have bad noise isolation
And the cheap 12v 3a can handle well

So i was rethink again
Its not from power supply i think there something wrong in circuit but i dont know where

Fyi
I already ordered
Ss54
And fmmt617(i dont know it would work or not but i just wanna try because in local supplier i live
I cannot found it

[Rtyuakatsuki]

Update

After changhing
Transistor to fmmt617
And diode schottky ss54

Replace atmega328p ic
I have 3 ic brand new ic

Got weird on off everytime pid used

Only pid

Direct control
Nothing wrong with it